Mental illness among adolescents frequently goes untreated, especially among low income and ethnic minority families. We sought to examine parent and adolescent psychological factors influencing mental health service use among 120 urban adolescents (82% African American, Age 13-18 years, M = 14.29, SD = 1.52) who had access to mental health treatment through their community primary care setting. We utilized structural equation modeling (SEM) to explore the independent and combined associations among parent and adolescent variables hypothesized to be associated with the youth's engagement in mental health treatment. Results showed that more than half (63.6%) of youth with clinically significant levels of symptoms were not currently engaged in treatment or seeking mental health services. One latent variable emerged: caregivers' perceptions of adolescent mental health problems (consisted of youth psychological symptoms, youth functional impairment, and strain on caregiver). Together with caregivers' attitude toward professional help, these two caregiver-reported variables, but not adolescents' attitude, were associated with higher likelihood of service utilization among adolescents. Findings suggest caregivers functioned as the "gatekeepers" to mental health services. We discuss findings' implications for engaging youth in mental health services as well as study limitations and future directions. (PsycInfo Database Record (c) 2020 APA, all rights reserved).